Can I ask how you set up the footing for your dry lot? I’m in South Central PA, likely very similar conditions to you. I’m looking to create about the same size dry lot for my 2 retirees. Currently I have a “clean slate” of a barn sitting in the middle of a small field of mixed grass/clover sod. Your set up sounds perfect. Everyone around here uses crushed stone but I’ve used a bit of millings around the entrance to the barn and it’s working well. Thank you.
Make sure you get double crushed asphalt, it is pulverized down to almost stone dust. Single crushed will have huge dutch oven sized chunks. We did not lay down any landscape fabric, though I know many people recommend it. We put down a 6-8" layer of double crush, level it with the FEL and pack it by running the tractor back and forth over and over… We try to keep the horses off of it for a period of time, the longer the better, and if it rains (or you water it) that helps to pack it in while it is “resting”. We also religiously pick up poop and hay, and never let it accumulate on top of the asphalt, or it quickly turns to mud/slime on top when wet. The asphalt gets tight enough that we can use the FEL to scrape the lot without disturbing the packed base. Super handy after the wet winter we had, when I could not pick daily, weekly or even monthly! My lot is pretty small, only 40x80, but I have always had a herd that can coexist peacefully in confined quarters. If you have a grumpy herd you may need to plan a bigger space…